Radiosonde recorder control



June 10, 1952 Filed July 8, 1946 J. A. SIDERMAN RADIOSONDE RECORDERCONTROL 2 SHEETS-SHEET l SLIDE WIRE T0 32 INPUT CIRCUIT /30 VOLTAGEDIvIDER I L vIERATOR 3'/ CONVERTER /-32 RECORDER INPUT 38TRANsFORMI-:R1f33 RECORDER VOLTAGE x34 MPL-E'R. MOTOR OR POWER CIRCUITAMPLIFIER /35 I I| I I6 BALANCE DE- #-7. A.C. TECTOR AND A BALANC'NG I5RECORDER courxoL MOTOR LSOURCE I2 FIG2. *1 *I INDICATOR i L L JINVENTOR.

JOSEPH A. sIDERMAN June 10, 1952 J. A. slDERMAN RADIOSONDE RECORDERCONTROL 2 SHEETS-SHEET 2 Filed July 8, 1946 FIGB.

FIGA.'

IIVVENTOR JOSEPH A. SIDERMAN Patented June 10, 1952 UNITED STATES OFFICE2,599,588- RADIOSONDE RECORDER GQNTBQL Joseph A- ,Sidermm Eefcntewn N-J- Application Julyv s, 194e, serial No. 631,949 4 Claims. (Cl. AZslif?)(Granted under the` act o1 March 3,

amended April 30, 1923;.l 37o o. G.

The invention described her-ein may be manufactured and used byor forthe Government for governmental purposes, without the payment to me ofany royalty thereon.

This inventionV relates to a recorder balance detector and recordercontrol and is particularly suitable for radiosonde recorderoperation.

One of the objects Vof this invention is to provide an electronicbalance detector and recorder control means which may be used with anyrecorder utilizing a balancing motor for moving a stylus or other'writing element.

Another object is to provide an arrangement where recording will besuppressed except when the stylus is in balance or near balance while inthe state of erraticity.

Still another object is to provide an arrangement for detecting avoltage supplied to the recorder balance motor to drive the recorder`toward a balance condition, which when subsequently reachedA will stopand the driving voltage will be nonoperating.

These and other objects will become apparent in the specification and inthe accompanying drawings in which:

Figure l shows the detector and control` circuit as used with aconventional recording system;

Figure 2 shows a block diagram of a'recorder;

Figure 3 shows a modied circuit for. the detector and control;

Figure 4 showsv a further modification of the detector and controlcircuit.

Recorders in general are provided with a stylus or writing element whichis moved by a balancing motor to a balanced position which correspondswith a value to be recorded on an. associated chart.

Upon receiving either an erratic measuring signal or` change in signalvalue the recorder seeks a new balance position. Ordinarily, movement ofthe stylus in seeking the new balanced position results in a line ormark on the record which is objectionable because of the difculty ininterpreting the recorded values. avoid ambiguities resulting from suchmarks and to retain a clean sharp record from which Values may be readaccurately and rapidly, it is desirable that the. recorder does notrecord during conditions ofr change. A recorded trace is desirable onlywhen the recorderis in a balanced condition and stable at such acondition, freefrom erraticity.

Asshown in` Figure 1, the signal from the phase and voltage controlcircuit in a conventional recording system is applied to terminals I 0.Across In order to' these terminals there is provided a condenser II. Abalance motor shownv generally at I2 is provided -with a pair ofwindings I3 and I4. Windings lf3 are connected across the output fromthe phaseV and voltage control circuit and are in parallel with4condenser II'. Windings I4 connect to an alternatingl current sourcethrough terminals I5; andiincluded` in the circuit of these windings isa condenser I6 for changing the phase. of` the alternating currentsource as applied to these windings. The primary winding Il of `atransformer I8 is also connected across the phase and voltage controlcircuit in parallel with condenser II and windings I3 rI-lhe secondaryI9; of' the transformer connects to a rectifier tube 20 as shown. Theoutput of the transformer after rectification by tube 20 is fed to thegrid` of a control tube 22. A resistor 'Ml and a condenser 23 areincluded in the circuit in the manner shown. A sensitivity control 24 inthe form of a potentiometer, or equivalent, is connected` to thecathodeof the control tube and to one. sidev ofA a control relay 25. While 25is shown asa control relay it should be noted that the relay may bereplaced by a recorder motor for a print circuit depending on theparticular recording system employed. For convenience in illustration adisc type recorder has been shown. Relay 25 controls a magnet coil 26which operates a lifting device 1y to raise the stylus arm 28 from therecord Ldisc 29. Operation of balance motor I-2fcontrols the angularposition of stylus arm 23 and` also Yslide wire potentiometer 3l bymeans of` a-control'shit36. The recorder is designated generally as 38.

' A complete circuit for a conventional recorder is shown in blockdiagram form in Figure 2, of a type, as f-or instance,` shown anddescribed on pages 298 to 300 of The Electronic Control Handbook by`Batcher and Moulic in their section Von Qontrol byftimed pulses(published in 194:6` by CaldwellClements, Inc., New York, N. Y), andincludes input circuit which feeds to a slide wire or equivalent 3| andto vibrator converter 32. Slide wire 3| has a source of voltage 40across itsixed outer terminals. The outputV from the vibrator converterand the slide Wire is fed to an input transformer 33 and to voltageamplifier 34. *The signal from the latter passesthrough a poweramplifier and phase controlv 3 5y to the balancing motor I2v which isalso supplied'with lpi'iwfer from an A.C. source as shown in detailinfFigure 1, and which drives the recorder 38 through a shaft 36 orequivalent couruling-means. The voltage in the balancing motor I2 issupplied to balance detector and print control 31, the circuit for whichhas been shown in detail in Figures 1, 3 and 4. The voltage fromdetector and control unit 31 is fed to recorder motor or circuit 25which for convenience is shown as a relay in Figures 1, 3 and 4. Element25 connects to recorder 38. An indicator, which may, for example, beaural or visual, is provided at 39 and is connected to operate when therecorder motor or circuit is either active or inactive depending on therequirements. Thus, an indicating lamp or buzzer may be activated upon achange in recorded value and would serve to attract the attention of anattendant or observer to this fact. Conversely it may be desirable tooperate such a signal only under conditions of steady value in whichcase relay 25 could be provided with contact means which would normallybe closed under conditions of stability. This indicator may operateentirely independently oi f the recorder if desired.

In operation the signal of the input circuit 33 of the recording systemin series with a balancing voltage across a portion of the slide wirefeeds to the vibrator converter and after passing through the inputtransformer is amplied at 34 and 35 and fed to the balancing motor I2.Referring now to Figure l, the voltage from power amplifier and phasecontrol 35 energizes windings I3 of balancing motor I2 driving it ineither dil rection depending upon the phase relationship between thevoltages of windings I3 and the voltages in windings I4 which areenergized by the external alternating current source. Assuming there isunbalance, balancing motor I2 rotates and drives the recorder 3B ofFigure 2 through shaft 35. The signal voltage in windings I3 is also fedthrough transformer I8 to the balance detector and recorder control 31(Fig. 2) which is shown in detail in the right hand half of Figure 1.

As long as there is unbalance in the balancing motor, the circuit of thebalance detector and recording control is energized and the recorder,through the action of relay 25 or its equivalent, the print circuit,depending on the system employed, is restrained. The circuit isenergized since the signal passes through the transformer I9 to berectified by the diode 23 to form a positive potential across resistor2| a positive increase in control grid voltage of triode 22 causing anincrease in the current through the energizing coil of the relay 25.This current produces an electromagnetic energy that can be used in anyof several ways well known in the art to prevent printing on the record.When the coil of relay 25 is not energized the printing proceedsnormally. Once balance is reached, or once erraticity is no longerpresent in amounts in excess of that corresponding to the setting ofcontrol 24 in Figure 1 or control 2i in Figures 3 and 4, the recorder isagain permitted to operate. rThe recorder may also be restrained whenthe rate of change of recorded value is excessive.

When the rate of change is reduced to a point determined by the settingof control 24 as being sufficiently small, the recorder is energized. Inthe circuit shown in Figure 3 the transformer coupling of Figure 1 hasbeen replaced by a capacitive coupling which includes capacitor 4E! andresistor 42. In this modiiication control of sensitivity is accomplishedthrough resistor 2l. Resistor 43 corresponds to resistor 24 of Figure 1.

Figure 4 shows a modiiication in which rectiiication is obtained througha bridge of selenium which represents or copper oxide rectilers 44 whichproduce fullwave rectiiication. Obviously any other convenient method ofrectication may be employed.

In systems utilizing a reversible D.C. motor instead of an A.C. motor inthe balancing mechanism, a rectifier is, of course, unnecessary, and anyone of numerous well-known circuits may be utilized. It is onlynecessary that the D.C. circuit be the equivalent of the A.C. circuitexcept for the rectifying function. Obviously, my invention can also beapplied to balancing mechanisms utilizing a voltage controlled movingcoil or phase controlled moving coil instead of the reversible A.-C. orD.-C. motor and can be used for indicating balance or unbalance by meansof any conventional visible or aural indicator.

The adjustable sensitivity control 24 is used to regulate theoperational range of the print control in the circuit of Figure l. riherecorder detector and recording control connects across the drivingwinding of the balance motor I2 so that if a Voltage is present it willbe rectied by tube 20 and applied to control tube 22 which in turncontrols the operation of the recorder, if an electronic recorder isemployed, or it controls the mechanical mechanism, if a mechanicalrecorder is used, by means of a control relay or torque by adjusting thesensitive control to the optimum position. Any erratic condition may beheld within a tolerable limit of the balanced condition. It is obviousthat the adjustment may be made so that only a very large voltageappearing across the balance motor winding such as is present when therecorder is moving from balanced position to another will activate thecontrol circuit. Thus, it is convenient to control the recorder topermit operation at any predetermined rate of change of value. Theadjustment may also be made so that a small fiuctuation in the recordedtrace may be made to control the circuit.

It is clear therefore that I have provided a simple and eicient meanswhereby the recording of any type of recorder may be so controlled afterpreventing spurious and undesirable marks on the record due toerraticity in the applied voltage or signal or during the period ofshift of the recorder mechanism from one balance condition to another.

While I have shown only two modifications of my invention it will beobvious to those skilled in the art that other arrangements, elementsand circuits may be employed in the practice of my invention and Itherefore do not limit myself except within the scope and extent of theappended claims.

I claim:

1. A system for recording varying values of a comparatively low inputvoltage, comprising a source of input voltage, an adjustable source ofbalancing voltage, means for connecting said input voltage and saidbalancing voltage in opposition to obtain a difference voltage, meansconnected to be energized by said difference voltage for deriving analternating current voltage proportional to said difference voltage, arecorder including a stylus for recording the value of said inputvoltage, electrical means coupled to said stylus for effecting a,movement thereof upon being energized, means directly connecting saidelectrical means to said voltage deriving means for effectingenergization of said electrical means, means coupled to and movable bysaid electrical means for adjusting said balancing voltage source toequal said input voltage, thereby causing said stylus to assume aposition determined by the value of said input voltage, means effectivewhen actuated for restraining said stylus from recording, and a circuitconnected to said voltage deriving means for eiecting actuation of saidrestraining means whenever said proportional voltage exceeds apredetermined value, said actuation effecting circuit including adetector for rectiiying said proportional voltage, a rectied voltageminimum value threshold element and means coupling said detector to saidrestraining means.

2. A system as defined in claim 1 wherein said actuation effectingcircuit further includes means for adjusting said threshold element tovary the value of the voltage at which said restraining means isactuated.

3. In a system for recording varying values of input voltage having asource of input voltage, means for deriving an alternating voltagehaving a value which is a function of the rate of change of said inputvoltage, a recorder including a stylus for recording the value of saidinput voltage, electrical means coupled to said stylus for eiecting amovement thereof whenever said electrical means is energized, meansdirectly connecting said electrical means to said voltage deriving meansfor effecting energization of said electrical means; an apparatus foruse with said stylus comprising means operative when actuated i'orrestraining said stylus from recording and a circuit for effectingactuation of said restraining means; said circuit including a detector,means for connecting said detector to said voltage deriving means forobtaining a rectied voltage therefrom, and means coupling said detectorto said restraining means for actuating said restraining means.

4. An apparatus as defined in claim 3 wherein said coupling meansfurther includes an amplifier having a bias control for adjusting thepredetermined value of the voltage from said voltage deriving means atwhich said restraining means is actuated; and a relay in the output ofsaid amplier for controlling the energization of said restraining means.

JOS-EPH A. SIDERMAN.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 2,207,343 Fairchild July 9, 19402,267,344 Fairchild July 9, 1940 2,392,916 Gruss Jan. 15. 1946 2,452,587McCoy Nov. 2, 1948 2,464,708 Moseley Mar. 15. 1949

